Implementing comma operator for asm->wasm.

test/mjsunit/wasm/asm-wasm.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --expose-wasm
 
 function EmptyTest() {
   "use asm";
   function caller() {
     empty();
@@ skipping 1024 matching lines @@
 
   var module = _WASMEXP_.instantiateModuleFromAsm(AsmModule.toString(),
                                                   foreign, null);
 
   module.__init__();
   assertEquals(103, module.caller(23, 103));
 }
 
 TestForeignFunctions();
 
+
 function TestForeignFunctionMultipleUse() {
   function AsmModule(stdlib, foreign, buffer) {
     "use asm";
 
     var getVal = foreign.getVal;
 
     function caller(int_val, double_val) {
       int_val = int_val|0;
       double_val = +double_val;
       if ((getVal()|0) == (int_val|0)) {
@@ skipping 157 matching lines @@
   m.storeb(20, 123);
   m.storeb(21, 42);
   m.storeb(22, 77);
   assertEquals(123, m.load(20));
   assertEquals(42, m.load(21));
   assertEquals(77, m.load(22));
   assertEquals(123, m.iload(0));
   assertEquals(42, m.iload(4));
   assertEquals(77, m.iload(8));
 })();
+
+
+(function TestComma() {
+  function CommaModule() {
+    "use asm";
+
+    function ifunc(a, b) {
+      a = +a;
+      b = b | 0;
+      return (a, b) | 0;
+    }
+
+    function dfunc(a, b) {
+      a = a | 0;
+      b = +b;
+      return +(a, b);
+    }
+
+    return {ifunc: ifunc, dfunc: dfunc};
+  }
+
+  var m = _WASMEXP_.instantiateModuleFromAsm(CommaModule.toString());
+  assertEquals(123, m.ifunc(456.7, 123));
+  assertEquals(123.4, m.dfunc(456, 123.4));
+})();